A One Size Fits All stretchy “over-hood” that covers all exposed skin. Holes for mask and breathing device can be trimmed to perfection by the user. Also provides excellent protection against Jellyfish in infested waters. A smart solution; just pull the H1 Icehood over your regular neoprene hood to get additional protection in really severe cold water diving-conditions. The H1 Icehood is also easily adaptable for use in tropical and warm water conditions, just cut out the facial parts and you have created your personalized Hood. Hypothermia vs Hoods. The body reacts to cold and heat by adjusting the blood stream to different parts of the body, like hands, fingers and feet. But the body can not adjust the blood stream to your head. This to ensure the brains function during all conditions. That is why the colder it gets, the more heat you loose from the head by radiation, or even worse, by conduction in the water. You keep warmer with an effective hood.